Hackers posted a step-by-step guide on how to poison unbelievers, which has already been downloaded by dozens of brainwashed followers.

The group, called Cyber Khilafah, uploaded the guide onto the Telegram app describing how to make the home-made poisons and kill non-Muslims.

The manual, titled “The Mujahideen Poisons Handbook,” details how to make dangerous poisons and gases along with listing lethal substances such as chlorine, phosphorus and carbon monoxide and where to get them.

Jihadi Abel Aziz authored the deadly guide, which is being used by ISIS terrorists.

The guide claims to have tested the lethal substances on animals, and details how a rabbit “shrieked immediately” and died with blood spilling from its mouth after being given poison by a wannabe jihadi.

Along with the detailed instructions and diagrams, the manual cautions would-be jihadis to be careful when preparing the concoctions.

It warns: “Be very careful when preparing poisons. It is much, much more dangerous than preparing explosives!

“I know several Mujahids whose bodies are finished due to poor protection etc.

“On the positive side, you can be confident that the poisons have actually been tried and tested (successfully, he he!).”

In the past, the Cyber Kahilafah group has targeted ISIS enemies on the Telegram app.

Guides on how to make IED bombs have been posted on the app by the group, which can be accessed by any follower from around the world.

The app is said to encrypt messages from users to help jihadis avoid detection from security services.

Terror expert Neil Doyle said: “The emergence of such guides on Telegram is a cause for great concern, as they can be distributed far and wide in a very short time.

“There is great danger in the proliferation of this type of material, as would-be terrorists may seek to use them to cause mayhem in so-called lone wolf attacks.

“Also, the use of encryption potentially make tracing the people receiving these documents more difficult for the authorities.

“There is evidence to suggest that this guide may have been used in one suspected failed attack in London some years ago.”

Adel Kermiche, who slaughtered an elderly priest in Normandy last month, boasted on the app “you take a knife, you go into a church, you cause carnage” before the savage killing.